Lean burn engine for automobile

ABSTRACT

A lean burn engine adapted to establish a specified air-fuel ratio leaner by predetermined rate than a stoichiometric air-fuel ratio in a range of low engine speeds and low engine loads is provided with an air intake system of a low speed type which provides a high charging efficiency in a range of low engine speeds and an exhaust system capable of eliminating a nitrogen oxide emission in the exhaust even during lean burning. &lt;MATH&gt;



